A control method automatically changing the light distribution of the headlamp according to the running environment of the vehicle is known as Adaptive Front-Lighting System (AFS). In this kind of control method, by detecting the running environment with a sensor, the headlamp is configured to rotate left and right around the vertical axis (i.e., swivel). Also, depending on the balance of the loads in the front and rear of the vehicle and the portion where the inclination of the road changes, the front portion of the vehicle body may be lifted or sunk down, and the vehicle body may be inclined slightly in the vertical direction relative to the road surface. A head lamp configured to change the irradiation angle (i.e., leveling) in the vertical direction of the headlamp by detecting such inclination with a sensor is conventionally known.
An apparatus configured to swivel a head lamp and to change the leveling is described in Patent Document 1. In the device described in Patent Document 1, the lamp unit is configured to be rotated in the lateral direction and the vertical direction of the vehicle by a swivel actuator and a leveling actuator.